Single buoy mooring for use in loading and unloading ship

ABSTRACT

SINGLE BUOY MOORING FOR FACILITATING THE LOADING AND UNLOADING OF STRIPS WHICH INCLUDES A FLOATING BUOY HAVING FLOATABLE FLEXIBLE CONDUIT MEANS OPERATIVELY ASSOCIATED THEREWITH IN SUCH A MANNER THAT THE CONDUIT MEANS IS ROTABLE ABOUT THE VERTICAL AXIS OF SAID BUOY AND ADDITIONALLY ROTABLE ABOUT A VERTICAL AXIS OFFSET FROM SAID BUOY VERTICAL AXIS.

NOV. 16, 1971 5 WESTRA 3,619,832

SINGLE BUOY MOORING FOR USE IN LOADING AND UNLOADING SHIP Filed July 25, 1969 2 Sheets-Sheet 1 Q g 2 Q I O b :2 b (\1 Q \N j N f/ .8 o 1 2 {J 8S, 0 J I 1 "m 2 O 07 N I '53 8 2 f 2 I 2 u. g Q 8 2 m N a 8 I a I m m L I no I o m f I H J IU N J I INVENTORI SIMON WESTRA HIS ATTORNEY NOV. 16, 1971 5 WESTRA 3,619,832

SINGLE BUOY MOORING FOR USE IN LOADING AND UNLOADING SHIP Filed July 25, 1969 2 Sheets-Sheet 2 v 0' o u.

INVENTORZ SIMON WESTRA United "States Patent 3,619,832 SINGLE BUOY MOORING FOR USE IN LOADING AND UNLOADING SHIP Simon Westra, The Hague, Netherlands, assignor to Shell Oil Company, New York, NY. Filed July 25, 1969, Ser. No. 844,998 Claims priority, application Great Britain, Aug. 2, 1968, 37,053/ 68 Int. Cl. B6311 21/50 U.S. Cl. 9-8 P 1 Claim ABSTRACT OF THE DISCLOSURE Single buoy mooring for facilitating the loading and unloading of ships which includes a floating buoy having floatable flexible conduit means operatively associated therewith in such a manner that the conduit means is rotatable about the vertical axis of said buoy and additionally rotatable about a vertical axis offset from said buoy vertical axis.

BACKGROUND OF THE INVENTION The invention relates to a structure for facilitating the loading and unloading of ships and more particularly to single buoy mooring for transporting fluids to and from tankers or similar vessels.

Single buoy moorings, for loading fluid into a ship, such as a tanker, or unloading fluid from such a ship, are known in the art. These known single buoy mooring buoys, which are in commercial use, are provided with flexible fluid conduits floating in the water in order to enable the ship to make a fluid communication between the ship and the buoy for loading or unloading a fluid. The floating flexible fluid conduit is easily damaged and is very expensive and thus it is desirable to find means to extend its useful life as much as possible.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an arrangement of a single buoy mooring wherein a number of features are incorporated having the effect of diminishing stresses on, and wear and tear of, the floating flexible conduit.

Consequently the single buoy mooring according to the invention comprises a buoy having a part rotatably secured in such a way that it is rotatable around a vertical axis, said part being provided with means for mooring a ship thereto. The buoy is anchored to the bottom of a body of water and a fluid supply or discharge conduit is operatively associated with the buoy. A fluid conduit is secured to the rotatable part and a coupling is provided between the fluid supply or discharge conduit and the fluid conduit secured to the rotatable part, said coupling allowing rotation around a vertical axis. A flexible fluid conduit floating in the water is connected at one of its ends by means of an elbow piece and a pipe swivel to the fluid conduit secured to the rotatable part, the pipe swivel allowing rotation around a vertical axis. The pipe part of the elbow piece which is adjacent to the floating flexible fluid conduit is inclined to the water surface and that section of the floating flexible fluid conduit adjacent to the elbow piece is of such buoyancy that it floats below the Water surface. The remaining part of the floating flexible fluid conduit has such buoyancy that it floats at the water surface.

DESCRIPTION OF THE DRAWING The invention will be explained with reference to the accompanying drawing wherein:

FIG. 1 shows a top plan view of a single buoy mooring according to the invention;

FIG. 2 shows a side view of the same single buoy mooring as shown in FIG. 1;

FIG. 3 shows schematically a top plan view of the single buoy mooring according to the invention, disclosing two diflerent positions of the floating flexible fluid conduits; and

FIG. 4 shows schematically a side view of the single buoy mooring as shown in FIG. 3.

Referring to FIGS. 1 and 2, a hollow cylindrical floating body 1 is provided with a rim 2 having means for securing anchor cables (not shown) thereto. The elements 1 and 2 form together a buoy suitable to be anchored in a body of water at a desired location. On the top of the body 1 a part 3 is rotatably secured in such a way that it is rotatable around a vertical axis. As shown in the drawings the rotatable part 3 has the shape of a turntable.

The rotatable part 3 is provided with means 4, such as bollards or similar devices, for securing mooring cables or chains of a ship thereto. A fluid supply or discharge conduit 5 is connected to the buoy, said conduit 5 leading to a reservoir (not shown), for example, to a reservoir located on-shore. On the rotatable part 3 is secured a fluid conduit 6 and a fluid conduit 6'. The fluid conduit 6 and the fluid conduit 6 are each in communication with the fluid supply or discharge conduit 5 through a coupling 7. The coupling 7 is constructed in such a way that it allows rotation around a vertical axis. In the conduits 6 and 6' valves 8 and 8', respectively, are present.

The respective lower ends of the fluid conduits 6 and 6' are each provided with a pipe swivel 9' and 9', connecting an elbow piece 10 and 10' to the fluid conduit 6 and 6' in such a way that each elbow piece 10 and 10' is rotatable around a vertical axis.

The lower pipe parts 11 and 11 of the elbow pieces 10 and 10' are inclined to the water surface 12. In the drawings the longitudinal axis of the pipe parts 11 and 11' is at an angle of 30 degrees with the water surface 12.

The floating flexible fluid conduits 13 and 13' comprise a number of sections of hose 14, 15, 16, 17, 18 and 14, 15', 16', 17, 18 interconnected in the usual manner by metal flanges 19 and 19. The said sections are provided with a number of annular floats 20 and 20 surrounding the conduits. These annular floats can suitably consist of foamed plastic.

The hose sections 14 and 14' are connected by means of flanges 21 and 21' to the pipe parts 11 and 11. The number of floats on the sections 14 and 15 and on the sections 14 and 15' is so chosen that the buoyancy of these sections, when filled with fluid to be pumped through it, is less than the buoyancy of the respective remaining parts of the floating flexible conduits 13 and 13, when filled with fluid to be pumped through them, the result being that, during normal use, the sections 14 and 15 and the sections 14' and 15' are floating below the water surface 12, whereas the remaining parts of the floating conduit 13 and 13' (in the drawings the sections 16, 17, 18 and 16, 17', 18') are floating at the water surface 12. As clearly shown in the drawings that part of the floating flexible fluid conduits, as represented by the sections 14 and 15 and the sections 14' and 15', are slightly curved, when at rest. As shown in the drawings, that part of the hose section 14 which is adjacent to the elbow piece 10, has a gradually diminishing wall thickness, so as to prevent hose kinking beyond the built-in steel nipple.

The use of the single buoy mooring according to the invention is the same as the known single buoy moorings as mentioned above, so that an explanation of this use would not seem to be necessary.

The special features as claimed have the advantage that the lifetime of the floating flexible fluid conduits is substantially increased as compared with the known single buoy moorings. In this respect attention is drawn to the fact that, because of the action of the waves, movement of the floating flexible fluid conduits 13 and 13 inwardly and outwardly relative to the buoy 1 normally occurs. This relative movement tends to cause damage to that part of the floating conduits 13 and 13' where the conduits are secured to the buoy. Now because of the curved part of the floating conduits 13 and 13', the elbow piece 10 and 10' and the pipe swivels 9 and 9', the curved part of the floating conduits 13 and 13' will be able to move vertically downward and at the same time laterally in a horizontal direction as shown in FIGS. 3 and 4 as the conduits 13 and 13 move inwardly relative to the buoy 1. In these FIGS. 3 and 4, the original position of the floating flexible fluid conduits 13 and 13 is shown in full lines, whereas the position of the floating flexible fluid conduits l3 and 13', after relative inward movement has occurred, is shown in dotted lines.

When two floating flexible fluid conduits are present,

as in the embodiment shown in the drawings, it is desirable to ensure that the floating flexible fluid conduits will move laterally in opposite horizontal directions as shown in FIGS. 3 and 4. This can be done by constructing the elbow pieces 10 and 10' in such a way that their flanges 21 and 21, adjacent to the floating flexible fluid conduits 13 and 13', are arranged somewhat excentrically in that the flanges 21 and 21' intersect the lower parts 11 and 11' of the elbows 10 and 10 so that an acute angle rather than a right angle is defined between the flanges 21 and 21 and the elbows 10 and 10" on the side of the elbow 10 facing the elbow 10' and on the side of the elbow 10' facing the elbow 10, as shown in FIGS. 1 and 3. This causes the floating flexible fluid conduits 13 and 13' to move outwardly and thus away from each other, so that they cannot get entangled as the conduits 13 and 13 move relative to the buoy 1 as shown in FIGS. 3 and 4.

I claim as my invention:

1. A single buoy mooring of the type which is anchored to the bottom of a body of water to provide an offshore fluid transfer facility for ships comprising:

a buoy having a part rotatably secured so that it is rotatable around a vertical axis, said part being provided with means for mooring a ship thereto;

a fluid supply or discharge conduit connected to the buoy;

first and second fluid conduits secured to the rotatable part;

coupling means between the fluid supply or discharge conduit and the first and second fluid conduits securing the first and second fluid conduits to the rotatable part, said coupling means allowing rotation of the first and second conduits around a verticle axis;

a first flexible fluid conduit floating in the water and connected with one of its ends by means of a first elbow piece and a first pipe swivel to the first fluid conduit secured to the rotatable part, the first pipe swivel allowing rotation of the first elbow piece around a vertical axis, said first elbow piece including first pipe means adjacent to the first floating flexible fluid conduit inclined to the water surface; said floating flexible conduit including a section vadjacent to the elbow piece having such buoyancy that it floats below the water surface, and the remaining part of the first floating flexible fluid conduit having such buoyancy that it floats at the water surface; second flexible fluid conduit floating in the water side by side with the first flexible conduit and connected with one of its ends by means of a second elbow piece and a second pipe swivel to the second fluid conduit secured to the rotatable part, the second pipe swivel allowing rotation of the second elbow piece around a vertical axis, said second elbow piece including second pipe means adjacent to the second floating flexible fluid conduit inclined to the water surface; said second floating flexible fluid conduit including a section adjacent to the elbow piece having such buoyancy that it flows below the water surface, and the remaining part of the second floating flexible fluid conduit having such buoyancy that it floats at the water surface; and a first and second flange disposed, respectively, on the first and second elbow pieces adjacent to the first and second floating flexible fluid conduits so that an acute angle is defined between the first flange and the first elbow piece on the side of the first elbow piece facing the second flexible fluid conduit and so that an acute angle is defined between the second flange and the second elbow piece on the side of the second elbow piece facing the first flexible conduit whereby inward motion of the first floating conduit relative to the buoy causes the first elbow piece to rotate about the vertical axis of the first pipe swivel in a direction such that the first floating conduit moves away from the second floating conduit and whereby inward motion of the second floating conduit relative to the buoy causes the second elbow piece to rotate about the vertical axis of the second pipe swivel in a direction such that the second floating conduit moves away from the first floating conduit.

References Cited UNITED STATES PATENTS 3,082,440 3/1963 Rhedin 9-8 P 3,190,495 6/1965 Mandel 98O P 3,332,093 7/1967 Skinner et al. 98 3,360,810 1/1968 Busking 9-80 P 3,365,734 1/1968 Petrie et al 980 P MILTON BUCHLER, Primary Examiner S, W. WEIN'RIEB, Assistant Examine; 

